Bag



.June 30, 1936. Q v. BRADY 2,046,146

BAG

Filed April 22, 1955 Patented June 30, 1936 UNITED STATES PATENT OFFICEBAG ration of Missouri Application April 22, 1935, Serial No. 17,585

6 Claims.

This invention relates to bags, and with regard to certain more specificfeatures, to bags particularly adapted for the packaging of powderedmaterial.

Among the several objects of the invention may be noted the provision ofa bag adapted to package powdered material, such as sodium aluminate,flour, powdered asphalt, insecticides, and the like, which, upon fillingthe bag, carry entrapped air, said bag being provided with a structurewhereby the entrapped airis immediately released, whereby a tightlyfilled bag is at once obtained; and the provision of a bag of the classdescribed which is simple in construction and economical to manufacture.Other objects Will be in part obvious and in part pointed outhereinafter.

The invention accordingly comprises the elements and combinations ofelements, features of construction, and arrangements of parts which willbe exemplified in the structures hereinafter described, and the scope ofthe application of which will be indicated in the following claims.

In the accompanying drawing, in which are illustratedseveral of variouspossible embodiments of the invention,

Fig. 1 is a perspective View of a bag embodying the present invention,certain seams being opened or unfolded in order to show the constructionof the bag.

Fig. 2 is a cross section taken substantially along line 2-2 of Fig. 1;

Fig. 3 is a greatly enlarged, diagrammatic cross section illustratingone form of the invention; and,

Figures 4 and 5 are sections similar to Fig. 3, illustrating furtherforms of the invention.

Similar reference characters indicate corresponding parts throughout theseveral views of the drawing.

It is a well known fact that certain finely powdered materials, such asthose above set forth, exhibit a tendency upon their being dischargedinto a bag, in the course of their packaging, to entrap quantities ofair which are not readily released from the mass of powdered material inthe bag, unless the bag is porous and hence not waterproof. There arenumerous instances when it iS necessary that such materials (which willbe referred to hereinafter as being puiy) be packaged in waterproofbags. In such instances, with prior types of bags, one of two proceduresneeded to be followed: (l) either the lled bag had to be allowed tostand for some time until the entrapped air all came to the top, andthereafter seamed shut, or (2) a bag of excessively great capacity forthe amount of material to be packaged needed to be employed. In the rstinstance, storage space was required during the settling of thematerial. In addition, the time element necessary for settling wasobjectionable. In the .second in- 5 stance, the larger bags for a givenquantity of material were necessarily more expensive, and in addition,when the air entrapped in the material finally did separate, the resultwas a abby, loosely packed bag.

The present invention provides a successful solution of the problem ofproviding waterproof bags for such puffy, powdered materials.

Referring now more particularly to Fig. 1, there is illustrated a bagmade in accordance with the 15 present invention. The bag comprises anouter envelope I, together with an inner envelope or tube 2. The outerenvelope I is formed of a laminated material (see Fig. 2), made up of afabric (usually burlap) layer 3 on the outside, to which 20 is adhered,by a cementitious layer 4, an inner paper layer 5. The cement 4frequently comprises asphalt or latex, either of which is eminentlysuitable. 'I'he paper layer 5 frequently comprises creped paper, as iscustomary in this art. This 25 laminated material is so formed that itis siftproof, waterproof, and otherwise impervious.

In forming the bag or envelope I from the laminated material thusconstituted, a sce-m 6 (see also Fig. 2) is made along the joinedlongitudinal 3U edges of the laminated fabric web. This seam 6 is soconstructed, that there is a region I provided in which the fabriclayers overlap each other, as well as a region 8, in which the paperlayers overlap each other. Adhesive material, such as latex, 35 isdesirably positioned in each of these overlapping positions, asindicated at numeral 9; but it is desirable that the adhesive 9 in theregion 8 be prevented from extending entirely to the end of said region,leaving a region Ill in which there '-0 is a loose overlap of paper. Theconstruction of the seam E is not a part of the present invention, andhence is not described in great detail herein.

The envelope I thus comprises a tube open at both ends. In order to formthis tube into a 4 bag, one end thereof is closed by a folded coverstrip II (see Figures l and 3) held in position by adhesive such aslatex. This construction is also claimed elsewhere. and per se forms nopart of the present invention. 5

The envelope I, it will readily be seen, is a complete bag in itself.However, it is so impervious or non-porous, that if it be attempted toll it with a powdered puffy material such as those hereinbeforeindicated, it does not provide for release of the entrapped air and allthe diiculties noted above are thus encountered. It is through the useofthe additional, inner envelope or tube 2 that these diiiculties areeliminated. The tube 2 preferably comprises a porous paper. Such apaper, for example, comprises an uncalendered, unsized or substantiallyunsized manila or like paper. It is .formed to tubular contour byoverlapping its edges and cementing or gluing them together in a simplelap seam I3 (see Fig. 2). The tube 2 is desirably made justenoughsmaller in diameter than the tube I, so that it will t easily butsnugly there- 1n.

In the finished bag, no separate closure is ordinarily provided forthe-bottom end of the tube 2. A portion of the cement which holds thecover strip II to the bag may penetrate into the interiorof the bag andlightly tack or secure the lower end of the envelope 2 to the lower endlof the envelope I. Thus, the envelope 2 may be held to the bag as acomposite unit.

The bag, as thus provided with the loose fitting paper liner 2, isextraordinarily effective for the packaging of powdered material such asthose described. The reason for this effectiveness is brought outdiagrammatically in Fig. 3, which is an enlarged cross section of anedge region on a filled bag. The paper layer 2, it will be recalled. isporous. This means that it will permit the passage therethrough ofentrapped air from the materials being packaged, indicated by numeralI5. At the same time, it' is not so porous that it would readily permitthe sifting therethrough of the material I5. It will be seen that theair initially entrapped with the inflowing material finds its way to theporous envelope 2 because the shortest exit distances through the massof material are lateral.

The creped paper layer 5 has, it will be understood, an irregularsurface I6. This surface I6 provides a large number of irregularchannels or passages I'I, all of which lead, through more or lessdevious paths, to the top of the bag. These channels I'I afford apassage from the bag for the entrapped air in the material I5, whichpasses through the porous paper layer 2. They are not clogged up by thematerial I5 itself, because the paper layer 2 substantially prevents thepassing of said powdered material therethrough.

It has been found that bags constructed in accordance with thisembodiment of the invention may be readily and quickly filled with themost puffy material, and that while the filling goes on, the materialpacks down firmly, allowing the immediate escape of all entrapped air,and permitting the bag to be solidly and completely filled and closedall in one immediate sequence of `op erations.

From the above it will be seen thatV the broader concept of theinvention is the provision of a double bag, the outer bag material beingsubstantially impervious and sift-proof, while the inner bag material isporous to lair, and the provision by non-matched surfaces between saidtwo materials of an interfacial region having passages or spacespermitting the outiiow of air from the bag.

Within this broad description, many other embodiments of the inventionare possible. For example, in Fig. 4 there is illustrated a constructionin which the paper liner 5 of the outer bag laminated material issmooth-surfaced, such as would be obtained when a kraft or similarcalthe market, in appearance.

endered paper is used as the liner. 'In order to provide an efcient bagwithin the present invention, when employing such a liner, it isdesirable that the bag layer 2 be formed of fluted porous paper. Theflutes are indicated by numeral I8. 5 They provide passages I9, ofregular shape and direction, for conducting the released air from thebag.

It is not even entirely necessary that the spaces corresponding to thepassages I'I of the Fig. 3 embodiment and I9 of the Fig. 4 embodiment beintentionally provided for. For example, if the smooth-surfaced liner 5of the Fig. 4 embodiment is used with a relatively smooth-surfacedporous paper layer 2, such as shown in the Fig. 3 embodiment, and saidlayer 2 is made of sufliciently stiff stock, it will be found that whenthe two bags are telescoped together, the natural stiffness of the bag 2prevents it, even when being filled, from lying flat against the paperliner layer 5 at all points. 'Ihere is always provided, by the naturalstiifness of the paper, a suilicient number of small spaces or regionsof non-juxtaposition to provide for the release of the air.

It is not necessary that the outer bag I be 25 formed of the laminatedfabric material heretofore described. In Fig. 5, for example, there isillustrated an embodiment wherein the outer bag may be formed of amaterial described and claimed in my copending application, SerialNumber 17,584, led April 22, 1935, which comprises a fabric layer 20having an inner layer 2I of the Goodyear 'Iire and Rubber Companysproduct Plioiilm securely adhered thereto. The Plioflm layer 2l is ofsimilar character to the transparent cellulose nlm or sheet nowavailable on It is absolutely waterproof in the combination with fabricas shown. It also provides a smooth inner surface. With this type oflaminated material, it is desirable to use a iluted inner porous paperlayer 2, as shown in Fig. 5, and which is similar to the analogous layerin the Fig. 4 embodiment.

The outer bag may also be made of impervious materials such as paperlacquered onits outer surface for appearances sake. It is not necessarythat the outer layer embody a fabric in order for it to constitute a.part of the present invention. Y

The word tu is used herein to describe the inner envelope of thecombination. It will of course be understood that the inner tube mayhave a. closed end, or (in the lled bag) ends. and thus comprise as muchan envelope as the outer envelope. 55

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructionswithout departing 6 from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawing shall be interpreted as illustrative and not in alimiting,85

with a plurality of passages whereby air can escape to the mouth of thebag.

2. A bag of the class described comprising an outer envelope' and a tubeassembled therein, said outer envelope being relatively waterproof, andsaid inner tube being porous to air, the interfacial region between theinner surface of said outer envelope and the outer surface of said innertube being provided with a plurality of air passages to the mouth of thebag.

3. A bag as set forth in claim 2, in which the outer envelope isprovided with an inner liner of creped paper, while the inner tube hasrelatively smooth outer surfaces.

4. A bag as set forth in cl 2, in which the outer envelope is formed ofa laminated material l0 comprising an outer layer of fabric, and aninner layer of smooth-surfaced paper secured to said outer layer by alayer of adhesive..

CHARLES V. BRADY.

